Resolve a system of two linear equations shortly utilizing this trick. It really works 100% of the time and also you waste no time, particularly in case you are taking an examination.

Trick #1:

Use when the system has the next format

x + y = e

x – y = f

x = (e + f)/2 and y = (e – f)/2

Instance #1:

x + y = 18

x – y = 6

x = (18 + 6)/2 = 24/2 = 12

y = (18 – 6)/2 = 12/2 = 6

Instance #2:

x + y = 9

x – y = 5

x = (9 + 5)/2 = 14/2 = 7

y = (9 – 5)/2 = 4/2 = 2

Trick #2:

Use when the system has the next format

ax + by = e

cx + dy = f

Instance #3:

3x + y = 5

2x + 3y = 8

Right here is how you can discover x in about 7 seconds

First rewrite every little thing with out the variables. When in search of x, discover how we cross out the numbers that had been hooked up to x to seek out the quantity on prime. Cross multiply as proven. Earlier than you multiply from backside to prime, put a subtraction signal.

Right here is how you can discover y in about 7 seconds

Once more, rewrite every little thing with out the variables. When in search of y, cross out the numbers that had been hooked up to y.